� national wetlands newsletter

National Wetlands Newsletter, Vol. 31, No. 4. Copyright © 2009 Environmental Law Institute.® Washington, D.C., USA. Reprinted by permission of the National Wetlands Newsletter. To subscribe call 800-433-5120, e-mail orders@eli.org, or visit www.eli.org

For more than a century, the techniques we have used in the United States to manage our diverse floodprone areas have centered on protecting human develop-ment—existing or potential—from flood damage and

on optimizing commercial benefits. The typical strategy has been to alter or confine a stream, river, lake, or coastline to a pre-defined size or capacity or shape that would maximize the extent of developable or agricultural land and also keep the flood water away from people and their property. Likewise, low-lying areas have been viewed as places to be dried out and filled in order to facilitate urbanization. An ancillary, more recent approach has been to ensure that residences and other structures built in floodprone places are elevated above some minimal flood level, so they are considered “safe,” and also to make insurance policies available to cover potential damage. In coastal areas, we typically have placed development, especially houses, as close to the water

Floodplain Management

as possible and then, if necessary, used structural measures to prevent the beach from migrating away.

Under this framework, floodprone areas have served only human-centered roles as water conveyance networks or as aesthetic or recreational conveniences, with no consider-ation given to their ecological function; the potential damage that human use might cause to other property owners within a watershed; or to the cultural, economic, or environmental effects of that strategy.

After many decades of this, we are still experiencing con-tinually rising flood losses. At the same time, environmental degradation of water-related resources has increased, and an-ticipated changes in climate may bring significant alteration of coastal areas, flood regimes, and already-fragile ecosystems.

As we move into the new century, we face hard choices about the management of our riverine and coastal flood-plains. In the next 20 years the U.S. population is predicted to increase by 80-90 million people, a huge increase over the current 300 million. The added population will increase pressure to continue to allow development adjacent to the nation’s water resources. Paradoxically, that population will still expect the nation’s flood risk to be minimized and will demand access to additional open spaces and natural areas. Relatively unfettered economic development, with only a to-ken allowance made for floodplain functions and resources, cannot continue as the status quo.

The substantial Midwest floods in 2008 were a reminder that our approach to managing floodplains does not adequately consider their ecological functions, which provide tremendous benefits to society. This article draws from a longer paper published in 2008 by the Association of State Floodplain Managers as Natural and Beneficial Floodplain Functions: Floodplain Management—More than Flood Loss Reduction.

By Dave Fowler and Jacquelyn Monday

Dave Fowler is a Senior Project Manager with the Milwaukee Metropolitan Sewerage District. He is a certified floodplain manager (CFM) and currently serves as the Region V Director for the Association of State Floodplain Managers (ASFPM) and was awarded the “River Hero Award” for his work on behalf of Milwaukee’s Rivers by the River Networks in 2005. Jacquelyn Monday is a geographer specializing in research and writing about environmental policy issues, especially floodplain and wetland management. She is the owner of JLM Associates, Inc., based in Grand Junction, Colorado.

More Than Flood Loss Reduction

July-August �009 �

Flooding as a Natural ProcessUnderstood in their proper role, floodplains provide society with tremendous benefits. Periodic flows of water that overtop the banks of a river and that encroach upon coastal areas are the lifeblood of our riparian corridors, marshes, beaches, and other natural areas. This flooding is a natural process that forms and maintains flood-plains and coastal zones, their landforms, their vegetative character-istics, and their role in broader ecosystems. The main processes and attributes of floodprone areas can be categorized as (1) hydrologic and hydraulic processes, (2) geomorphic processes, and (3) biologic processes. All of these have interrelated functions that, when operat-ing in their natural state, provide such tangible benefits as increased soil fertility, wetland creation, rejuvenation of spawning gravel, cre-ation of barrier islands, promotion of aquatic habitat, transporta-tion of large woody material that provides fish habitat and bank stability, promotion of plant establishment, and the evolution of channels and shoreline features such as dunes.

Hydrologic and Hydraulic ProcessesBoth river and coastal ecosystems are shaped and nurtured by the characteristics of the water. The seasonal and storm-generat-ed variations in water flow, including periodic flooding, are part of the normal function of the floodplain zone. These variations mold streambanks, keep erosion and accretion in equilibrium, replenish soils, recharge groundwater, and filter impurities. In coastal areas, water differences are based on tides, currents, wave action, and storm surges—all of which form shorelines, coastal wetlands, dunes, barrier islands, and estuaries. High flows in both areas are critical to maintaining vegetation because they transport sediment and nutrients from the river, ocean, or lake to the connecting floodplain.

Geomorphic ProcessesThe dimensions and configuration of a stream channel or coastline are determined by ongoing geomorphic processes. For example, the natural transport of sand and sediment dictates the migration of channels, shorelines, dunes, and barriers. This process, in turn, is influenced by the geological composition of the landforms; the caliber, rate, and volume of sediment movement; and the pres-ence or absence of vegetation. Although the geomorphology of waterways and shorelines is constantly changing, in their unal-tered state they exist in dynamic equilibrium, which cannot be disturbed without consequences.

Biologic ProcessesFloodplain and coastal vegetation helps to stabilize the shoreline and river banks, provide habitat for terrestrial and aquatic wildlife, control erosion and sedimentation, and improve water quality by filtering pollutants. Healthy ri-parian corridors often provide the highest concentrations of plant and animal communities in a watershed, providing a stable source of biodiversity. The variable flows of water in riparian and coastal areas have resulted in uniquely adapted species of aquatic and terrestrial organisms—they depend

on the variation in water conditions for spawning, seed dis-persal, elimination of competing vegetation, and nursery areas for their young.

Interruption of Natural ProcessesHuman activity disrupts the tightly interconnected functions of natural riparian and coastal areas described above and thus under-mines the overall health of the ecosystem. This is especially true of urbanization and also of our attempts control water.

A stark example of the long-term effect of such interruption can be found in the tragedy that Hurricane Katrina brought to New Orleans. The complex interaction between the coastal wetlands and the Mississippi River had not been understood in earlier decades. Long-term projects to increase flood protection and navigation ef-ficiency along the Mississippi River employed an extensive levee system. These levees cut off the supply of sediment to the coastal wetlands, which then began to shrink. The shrinkage was exacerbat-ed by extensive dredging of the wetlands for a range of development and navigation purposes. Without their energy-absorbing capacity, the impact of storm surges and hurricanes to New Orleans and the Gulf Coast increased. Damage from Katrina was much more severe because these natural buffers had been lost.

Less obviously, in our attempts to transport runoff and flood waters efficiently through our watersheds, we have used structural interventions (concrete lining, revetments, floodwalls, jetties, di-versions, and dams and reservoirs) that interrupt or modify natu-ral hydrologic, hydraulic, geomorphic, and biologic processes. The ground surface and natural vegetation are disturbed during construction. The structures change the natural movement of wa-ter by altering its speed, restricting movement across the flood-plain, or changing sediment loads. Floodwalls and levees increase flow discharge and elevation when they constrict high flows into a narrow path. Land use policies that allow encroachment into the floodplain can cause dramatic channel migration downstream. Changing the frequency of floodplain inundation can encourage invasive species to supplant the native vegetation.

Activities in pursuit of development, urbanization, and flood protection have yielded specific—usually localized—eco-nomic and social benefits, but the long-term impacts have placed both humans and nature at higher risk. Further, they have proved counterproductive, resulting in a system of “reactive” engineering through which the symptoms of the problem are treated at great expense while the underlying causes are not addressed. Decades of this approach have destroyed a large proportion of our wetlands,

“Activities in pursuit of development, urbanization, and flood protection have yielded specific—usually localized—economic and social benefits, but the long-term impacts have placed both humans and nature at higher risk.”

� national wetlands newsletter

deprived our river deltas of sediments needed to maintain marsh-es, prevented nutrient-rich flood water from reaching adjacent lands to replenish the soils, interrupted the protective functions of coastal barriers, and contributed to declines in water quality. Flood losses continue to rise, and we are witnessing the gradual destabilization of watersheds and coastal areas and loss of natural function—death by a thousand tiny impacts.

A Call for Renewed DirectionPressures to make use of floodplains and coastal areas for human development will continue to mount, and the techniques we are using today are allowing that development to interrupt the natural functions of those areas and result in environmental degradation. To counteract this, we must alter two long-standing attitudes.

The first is the widespread view of floods as destructive forces of nature. Floods do not cause damage or suffering. Our decisions about where to live, work, and play are the cause. Instead of controlling the water, we should control how and where we allow human activities to adversely affect it and the land areas to which it is naturally linked.

Second, it must become unacceptable to obtain short-term reductions in flood risk and/or short-term economic gains by

shifting the costs of those benefits onto the environment and onto future generations. Instead, we need to work toward ensur-ing the long-term environmental and economic sustainability of our floodplain ecosystems.

National Policy NeededToday the nation’s floodprone lands and its waters are subject to an impressive array of laws, policies, programs, and activi-ties at all levels of government and within the private sector. These include federal environmental protection laws such as the Clean Water Act, the Endangered Species Act, and the Na-tional Environmental Policy Act (along with some state-level counterparts); federal laws that have other, varying purposes such as the Water Resources Development Act, the National Flood Insurance Program, and the Disaster Relief and Emer-gency Assistance Act (along with some state-level counter-parts); state programs for dam safety, highway and bridge construction, and parks; and local laws and programs for com-prehensive planning, stormwater management, and building code enforcement—all of these to name just a few.

None of these, however, has the comprehensive goal of pro-tecting floodprone areas in recognition of their natural values and

Photos courtesy of Ed Edahl and Andrea Booher (window) /FEMA

In mid-May, 35 days after the Red River flooded, the view at the Minnesota-North Dakota border shows how much of the area’s floodplain remains under water. In the picture window, a resident in Moorhead, Minnesota, walks through the same flood in late March.

July-August �009 9

Resources

The natural functions and resources of floodplains are described in detail in numerous documents, notably A Unified National Program for Floodplain Management (Federal Interagency Floodplain Management Task Force, 1994) and The Natural & Beneficial Functions of Floodplains (Task Force on the Natural and Beneficial Functions of the Flood-plain, 2002). Available at www.fema.gov/pdf/fima/fema100.pdf.

Natural and Beneficial Floodplain Functions: Floodplain Manage-ment—More Than Flood Loss Reduction contains numerous recommendations for revisions to national policy that would operate to protect and restore the nation’s floodprone lands. Access it and other ASFPM White Papers on the ASFPM website at www.floods.org/NewUrgent/Other.asp.

In Related newsThe U.S. Department of Agricul-ture (USDA) awarded 289 flood-plain easements to return more than 36,000 acres of floodprone land back to its natural state. The American Recovery and Reinvest-ment Act set aside $145 million for the first national floodplain easement effort, which will benefit lands in 36 states. USDA received over 4,000 applications for nearly a half million acres across 47 states. Read more at www.usda.gov/wps/portal/usdahome?contentidonly=true&contentid=2009/06/0191.xml.

The Federal Emergency Manage-ment Agency (FEMA) announced at the Association of State Flood-plain Managers Annual Confer-ence in Orlando, Florida, that it will study the effects of global warming on inland floodplains and coastland, as well as the risks that sea level rise presents to the National Flood Insurance Program. FEMA expects to release the results in March 2010.

and businesses away from the high-hazard and eco-logically sensitive areas along our coasts and rivers. State and local governments can guide future devel-opment completely away from these areas by apply-ing land use planning and management techniques. This is the most effective way to minimize cumulative flood-related losses and to halt the degradation of our water-related resources.

Restoration of Floodplain and Coastal ResourcesRehabilitating the riparian and coastal resources and the natural buffers that we have lost needs to become a national priority. We should work toward widespread understanding of the short-term and long-term environmental impacts of human-made flood and coastal protection measures and how those impacts can be mitigated.

Recognition of Natural Functions and ResourcesTo effectively incorporate the protection of flood-plain and coastal functions in our management strategies, we need to adopt a multidisciplinary ap-proach that integrates land use planning, hydrology, hydraulics, geomorphology, biology, botany, stream ecology, and other fields. Specific multi-objective criteria are needed that balance social, economic, and environmental issues with an eye on long-term social and environmental sustainability. The actual short-term and long-term economic and other ben-efits of naturally functioning coastal areas and river-ine floodplains must be quantified so that they can be properly accounted for in cost-benefit analyses and other decision-making tools.

References

Association of State Floodplain Managers Foundation. 2008. Floodplain Management 2050: A Report of the Second Assembly of the Gilbert F. White National Flood Policy Forum. ASFPM Foundation, Madison, WI.

Association of State Floodplain Managers. 2007. National Flood Programs and Policies in Review 2007. ASFPM, Madison, WI.

Association of State Floodplain Managers. 2003. No Adverse Im-pact: A Toolkit for Common Sense Floodplain Management. AS-FPM, Madison, WI.

Federal Interagency Floodplain Management Task Force. 1994. A Unified National Program for Floodplain Management. Federal Emergency Management Agency, Washington, D.C.

Task Force on the Natural and Beneficial Functions of the Flood-plain. 2002. The Natural &Beneficial Functions of Floodplains: Reducing Flood Losses by Protecting and Restoring the Floodplain Environment. A Report for Congress. FEMA 409. Federal Emer-gency Management Agency, Washington, D.C.

functions—indeed, many operate at cross-purposes. Further, there is no over-arching vision or statement of the nation’s policy, nor is there any mechanism by which all the laws, guidelines, policies, programs, and projects can be coordinated so that a sustainable fu-ture can be achieved. Congress should enact a nation-al policy that establishes unequivocally the inherent value of the natural functions and resources of flood-plains and coastal zones and their role in minimizing flood losses. This policy should set clear priorities for protecting the natural functions of our waterways, coastlines, and adjacent land areas and also for restor-ing those that have already been degraded, with the goal being long-term sustainability of those systems, in order to benefit society.

In line with this new vision, many existing procedures will need to be adjusted. A few exam-ples are listed below.

• Existing regulatory programs that give higher priority to damage reduction than to floodplain protection should be revamped. Such regulations assume that floodplain and coastal development is going to occur and then proceed to guide the design and construction of it—the opposite of the pre-ferred approach. • New guidance should foster a reduced need for—and reduced expectation of—federal flood control measures in communities in or near floodplains and coastal zones. • The plans and designs of any future levees should take into account the impacts the le-vee would have on the hydraulic, biologic, and geomorphic processes of the watershed.• Environmental mitigation should be re-quired as a condition of receiving federal financial assistance after a flood, instead of reconstruction to pre-flood conditions without considering mitigation or environ-mental restoration.• The rules for reviewing proposed flood-re-lated projects must be revised to account for the environmental benefits of a project, just as environmental compliance is included as a cost. Projects whose aim is to restore the nat-ural and beneficial functions of floodplains, for example, must be allowed to compete fairly with other proposed projects.

Voluntary Retreat From Floodprone AreasWherever it can be done—at the individual, neigh-borhood, community, state, or national level—we need to begin to gradually relocate existing residences